[DavidG]

The difference is straight forward. Randolph's and your New Zealand example's bodies were manufactured by the New Zealand and South African parent company, Ford of Canada whose overall production was LHD in the main and whose bodies were the same as those of Ford U.S..

While Ford Australia was also a Ford of Canada subsidiaty, its bodies were home grown and only in RHD form. Note in Trrevor's photos how even the shape of the rear window opening differs between the bodies. The Australian coupe quarter windows are also quite different plus the sills do not extend to the top of the running boards unlike the bodies of Canadian and U.S. manufacture.